Xiaomi Smart Air Purifier 4 Filter Unavailable

I can't find a filter for the Xiaomi Mi Smart Air Purifier 4. I got it in February 2023, and it hasn't even been a year. The filter is almost empty, but I can't find it anywhere. The tech support is not responding and telling me to check online. I've looked everywhere, but I can't find it. The device is useless if it doesn't have spare parts. Why are you selling it if you can't give spare accessories? It's like we're expecting it for free. I bought this device because I have really bad allergies. If I can't find the parts, I'll have to purchase a new device. I'm really let down by your brand, even though it was supposed to be really good. I need a quick solution. If you don't have spare parts, please give me a new device later on!